全文获取类型
收费全文 | 2389篇 |
免费 | 77篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 159篇 |
妇产科学 | 71篇 |
基础医学 | 185篇 |
口腔科学 | 75篇 |
临床医学 | 178篇 |
内科学 | 419篇 |
皮肤病学 | 51篇 |
神经病学 | 141篇 |
特种医学 | 271篇 |
外科学 | 436篇 |
综合类 | 133篇 |
预防医学 | 63篇 |
眼科学 | 85篇 |
药学 | 127篇 |
1篇 | |
肿瘤学 | 90篇 |
出版年
2023年 | 17篇 |
2022年 | 21篇 |
2021年 | 26篇 |
2020年 | 19篇 |
2019年 | 15篇 |
2018年 | 25篇 |
2017年 | 36篇 |
2016年 | 58篇 |
2015年 | 58篇 |
2014年 | 71篇 |
2013年 | 136篇 |
2012年 | 154篇 |
2011年 | 166篇 |
2010年 | 100篇 |
2009年 | 99篇 |
2008年 | 163篇 |
2007年 | 201篇 |
2006年 | 175篇 |
2005年 | 158篇 |
2004年 | 126篇 |
2003年 | 78篇 |
2002年 | 67篇 |
2001年 | 37篇 |
2000年 | 25篇 |
1999年 | 25篇 |
1998年 | 47篇 |
1997年 | 44篇 |
1996年 | 43篇 |
1995年 | 27篇 |
1994年 | 26篇 |
1993年 | 24篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 29篇 |
1988年 | 19篇 |
1987年 | 15篇 |
1986年 | 21篇 |
1985年 | 28篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 19篇 |
1981年 | 10篇 |
1980年 | 13篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1955年 | 2篇 |
1953年 | 2篇 |
排序方式: 共有2509条查询结果,搜索用时 15 毫秒
111.
DC Wilson MJ Cunningham MMcC Reid SS Johnston TF Fannin 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(1):84-85
A baby with unilateral cleft lip, midline cleft palate and hypertelorism developed meningitis in the first 48 h of life. Examination of the nasopharynx showed a soft tissue mass, which was confirmed as a basal encephalocele by computed tomography. There was also congenital hydrocephalus and the corpus callosum was absent. Surgical treatment included repair of the anterior basal skull defect, repair of the lip and palate, and ventriculo-peritoneal shunt. There is currently evidence of developmental delay and right-sided visual impairment due to Morning Glory syndrome. This case demonstrates that basal encephalocele should be considered in any baby with midline facial deformity who develops meningitis. 相似文献
112.
Berrin Acar Cemal Posaci MD Oguz Dicle MD Atakan Topuz MD Oktay Erten 《The Australian & New Zealand journal of obstetrics & gynaecology》1992,32(3):252-255
In this study 23 patients with various gynaecological pathologies were evaluated. Ultrasonography and magnetic resonance imaging were performed in all cases, but only 14 were evaluated with computed tomography. On the basis of ultrasonography, 4 patients were labelled as having malignant ovarian tumours, however, this diagnosis was confirmed by magnetic resonance imaging in only 1 of the 4. Magnetic resonance imaging also determined the correct diagnosis in a patient with endometrioma whereas computed tomography showed only a simple cyst, and ultrasonography diagnosed a subserous myoma. Tumour was demonstrated by magnetic resonance imaging in 2 patients with cervical carcinoma although computed tomography and ultrasonography had previously shown no tumour mass in these patients. It was concluded that magnetic resonance imaging is much superior to computed tomography and ultrasonography in gynaecological diagnosis. This advantage results from the correct detection of the contents of ovarian cysts, the number and localization of uterine leiomyomas in T2 scans, invasion of uterine malignancies and differential diagnosis of subserous uterine leiomyomas from ovarian tumours. 相似文献
113.
PURPOSE: To investigate the relationship between the radius of tear meniscus curvature (TMR) and tear meniscus height (TMH). METHODS: Twenty-nine eyes of dry-eye patients (all left eyes; two males, 27 females, aged 26 to 85 years [mean +/- SD; 60 +/- 14.4]) were enrolled in the study. TMR was measured at the tear meniscus of the central lower lid with a newly developed videomeniscometer. At the same region of the eye, TMHs were measured without fluorescein (TMH-M) and after 5 minutes with fluorescein (TMH-MF), using a slit lamp equipped with a micrometer. TMHs were also measured on cross-sectional photographs of the fluorescein-stained meniscus (TMH-P). RESULTS: The values of TMR, TMH-M, TMH-MF, and TMH-P (mean +/- SD, mm) were 0.22 +/- 0.09, 0.19 +/- 0.09, 0.21 +/- 0.14, and 0.24 +/- 0.09, respectively. There was significant correlation between TMR and TMH-M, TMH-MF, and TMH-P values (TMR versus TMH-M: r = 0.596, p = 0.0005; TMR versus TMH-MF: r = 0.587, p = 0.0006; TMR versus TMH-P: r = 0.605, p = 0.0003). CONCLUSION: There is a significant correlation between TMR and TMH. Videomeniscometry has some merits over conventional methods for obtaining tear meniscus parameters. 相似文献
114.
Secondary transplantation following a period of isografting: experimental study in rats 总被引:1,自引:0,他引:1
Yenidünya MO Dongyoung Y Yenidünya S Hriscu M Tosa Y Uemura T Hosaka Y Morohoshi T 《Journal of reconstructive microsurgery》2002,18(2):121-8; discussion 129
The authors describe a study in which groin flaps from 20 Wistar rats were transplanted to another group of 20 Wistar rats and, after various time intervals, the groin flaps were re-transplanted back to the original animals. The goal of the first transfers was to preserve the flap in the second group of animals (isopreservation). During the isopreservation period, the second rat (the preserver) was treated with steroids or FK506 for immunosuppression. Thirty-three free groin flap transfers were performed between 40 rats. If possible, the same flap was transferred twice between two animals, one as an isograft, and other as an autograft following an isopreservation period in 13 pairs of animals. (A second transfer was not possible in seven pairs of animals.) The period for isopreservation varied between 2 days and 1 week. The survival of the flap was observed by visual inspection, laser Doppler flowmeter measurements, and was correlated with serial histopathologic examinations of skin and vessel biopsy specimens, including the anastomosis site. The severity of histopathologic signs that might be related to developing rejection was increased by the preservation time, and was more noticeable after the second transfer. The authors showed that successful secondary transplantation of the rat groin flap with a 1-week follow-up could be achieved, following isopreservation of at least up to 5 days. 相似文献
115.
Tuncok Y Kalkan S Murat N Arkan F Guven H Aygoren O Kurt S 《Journal of toxicology. Clinical toxicology》2002,40(2):121-127
OBJECTIVE: Hypotension induced by tricyclic antidepressants is multifactorial. Previous animal experiments suggest a contribution from nitric oxide production. Our study aimed to evaluate the role of nitric oxide in amitriptyline-induced hypotension using N-nitro-L-arginine methyl ester, a nitric oxide synthesis inhibitor, and 3-morpholino sydnonimine, a nitric oxide donor, in anesthetized rats. METHODS: Amitriptyline intoxication was induced by the continuous infusion of amitriptyline 0.625 mg/kg/min throughout the experiment in anesthetized rats. Fifteen and 25 minutes after amitriptyline infusion began, two bolus doses of 10 mg/kg of N-nitro-L-arginine methyl ester (n = 8) or an equivalent volume of 5% dextrose solution (n = 8) was administered to each rat (Protocol 1). To investigate whether the effect of N-nitro-L-arginine methyl ester on blood pressure is counteracted by 3-morpholino sydnonimine, after the same protocol of amitriptyline infusion and 5 minutes after an N-nitro-L-arginine methyl ester bolus, a bolus of 3000 nmol/kg of 3-morpholino sydnonimine was administered (n = 8) to each rat (Protocol 2). To investigate the effect of N-nitro-L-arginine methyl ester on 3-morpholino sydnonimine induced hypotension, a group of rats received a continuous infusion of 0.54 mg/kg/h of 3-morpholino sydnonimine until 50% reduction was observed in mean arterial blood pressure followed by a bolus dose of 10 mg/kg of N-nitro-L-arginine methyl ester (n = 6) or 5% dextrose solution (n = 6) (Protocol 3). Outcome measures included mean arterial blood pressure, heart rate, and QRS duration in electrocardiogram. Student's t test and survival analysis were used for selected comparisons. RESULTS: For all parameters, the treatment groups were similar at baseline and at postamitriptyline periods before therapy was rendered. Amitriptyline infusion significantly reduced mean arterial blood pressure by 50.8 +/- 2.2% and prolonged QRS by 23.9 +/- 7.2% after 15 minutes. In Protocol 1, N-nitro-L-arginine methyl ester significantly increased mean arterial blood pressure compared to dextrose-treated control animals within 30 minutes (77.9 +/- 8.5% vs. 49.7 +/- 5.0% mmHg, p < 0.01, 95% CI 57.1-98.7%). QRS duration progressively increased during the amitriptyline infusion; however, there was no significant difference in QRS width between N-nitro-L-arginine methyl ester and control groups at any time point. N-nitro-L-arginine methyl ester increased survival time compared to controls (33.4 +/- 4.1 vs. 19.9 +/- 2.7 minutes, p < 0.01, 95% CI 25.4-41.3) but did not affect mortality. In Protocol 2 of continuous infusion of amitriptyline, 3-morpholino sydnonimine counteracted the N-nitro-L-arginine methyl ester-induced increase in mean arterial blood pressure. In both protocols, heart rate decreased significantly during amitriptyline infusion but there was no difference between treatment and control groups. In Protocol 3, N-nitro-L-arginine methyl ester bolus reversed 3-morpholino sydnonimine-induced hypotension compared to dextrose bolus. (83.8 +/- 5.7% vs. 54.6 +/- 4.8%, p < 0.01, 95% CI 69.2-98.4). CONCLUSION: N-nitro-L-arginine methyl ester is found to be effective in temporarily improving hypotension and prolonging survival time but does not affect overall mortality. Because this effect was antagonized by 3-morpholino sydnonimine, nitric oxide production appears to contribute to the pathophysiology of amitriptyline-induced hypotension. 相似文献
116.
117.
Caksen H Dülger H Cesur Y Odabaş D Tuncer O Ataş B 《The International journal of neuroscience》2002,112(11):1371-1374
In this study, we studied serum calcium, phosphorus, alkaline phosphatase, thyroid hormones (total thyroxine, free thyroxine, thyroid-stimulating hormone), parathyroid hormone, and osteocalcine levels in children with epilepsy who had been receiving long-term valproate (VPA) therapy in order to determine whether there was any effect of VPA therapy on these hormones. The study included 31 patients with epilepsy receiving VPA and 22 healthy age-matched controls. The age ranged from 15 months to 16 years and 18 months to 17 years in the study and control group, respectively. The duration of VPA use was between 12 months and 5 years (1.93 +/- 1.90 years). When comparing the results, we did not find any significant difference in any of the parameters, including serum calcium, phosphorus, alkaline phosphatase, osteocalcine, and thyroid and parathyroid hormone levels, between the study and control group. We suggest that VPA can safely be used with regard to thyroid and parathyroid dysfunction in childhood epilepsy. 相似文献
118.
Akgul E Inal M Soyupak S Binokay F Aksungur E Oguz M 《Acta radiologica (Stockholm, Sweden : 1987)》2002,43(3):315-319
PURPOSE: To review the distribution of intrahepatic portal venous branching in order to determine the prevalence of variations. MATERIAL AND METHODS: We made a retrospective review of 655 contrast-enhanced helical CT (CECT) images of patients referred to our department for upper abdominal CT examination during an 8-month period. Of the 655 patients, 70 were eliminated from the study because of improper opacification of the portal venous system. Variations of portal venous branching in the remaining 585 patients were classified. RESULTS: Of 585 patients, 504 (86.2%) had classical bifurcation of the main portal vein (MPV); 72 (12.3%) had a trifurcation of the MPV, 5 (0.9%) had a right anterior segmental branch originating from the left portal vein (LPV), 2 (0.3%) had an LPV originating from the right anterior segmental branch and 2 (0.3%) had a right posterior segmental branch arising from the MPV. CONCLUSION: Variations of portal venous branching are common and helical CT is efficacious in identifying these variations. 相似文献
119.
Impact of pager notification on report verification times 总被引:2,自引:0,他引:2
RATIONALE AND OBJECTIVES: The purpose of this study was to assess the impact on times of verification (TOVs) by a pager notification system (PNS) that informs physicians when reports are available for signature. MATERIALS AND METHODS: An automated PNS was implemented in the authors' department in November 2000. Monthly report verification times of each physician were collected for 3 months in the years before and after initiation of the PNS. Radiologists enrolled in the PNS and those who were not were assigned into two groups for analysis. Mean TOVs for the two sets of 3 months and for the two groups were calculated and differences recorded. Two-tailed t tests were used to assess for statistical differences between the groups. RESULTS: Twenty-nine of 37 radiologists voluntarily enrolled in the PNS (group 1). Mean TOV was 26.75 hours (standard deviation [SD] = 17.76) for these physicians before and 14.48 hours (SD = 11.86) after the PNS was employed (P < .01). For those physicians who did not enroll in the PNS, mean TOV was 11.53 hours (SD = 5.55) before and 9.77 hours (SD = 9.86) after the PNS was employed (P = .33). Both the absolute and percentage reductions in TOVs were significantly greater for those physicians enrolled in the PNS than for those who were not (P = .035). Twenty-three of 29 (79%) physicians who used the PNS showed a reduction in their report turnaround times. CONCLUSION: Linking the PNS with the radiology information system to notify physicians of unsigned reports was effective in reducing report verification times. 相似文献
120.
Mikhelashvili-Browner N Yousem DM Mandir AS Calhoun VD Wu C Oguz KK Vaughan CL 《Academic radiology》2002,9(5):513-519
RATIONALE AND OBJECTIVES: The authors performed this study to determine whether reaction times (RTs) recorded in the functional magnetic resonance (MR) imaging environment reflect the performance of the patient outside the imaging room. MATERIALS AND METHODS: Fifteen healthy control subjects (mean age, 61.6 years) performed a simple reaction time (SRT) task outside the MR magnet and a visuomotor response time task inside the magnet with use of block-design and event-related paradigms. For both behavioral and functional MR imaging tests, subjects tapped the right index finger upon the appearance of a visual cue. The mean RTs for out-of-magnet and functional MR imaging paradigms were compared. Results. There was a statistically significant difference in RTs between block-design and single-event paradigms (t = 3.458, P < .004). The RT values during functional MR imaging and SRT tasks did not show significant differences (.65 < P < .7, paired t test). However, no correlation was found in RT values between event-related (p = -0.004, P = .15) or block-design (p = 0.03, P = .13) paradigms and SRT data. With the block-design functional MR imaging paradigm, the RT was significantly faster (P < .0003) at the beginning of the session than the end, illustrating the effect of anticipation. CONCLUSION: Functional MR imaging RTs must be used to determine the correlation between subjects' performance and the volume of brain activation in a functional MR imaging experiment. The effect of anticipation should be minimized, which could best be achieved by using event-related paradigms. 相似文献